From: "Lad, Prabhakar" <prabhakar.csengg@gmail.com>
To: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
Rob Herring <robh+dt@kernel.org>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
Hans Verkuil <hverkuil@xs4all.nl>, Shawn Tu <shawnx.tu@intel.com>,
Jacopo Mondi <jacopo@jmondi.org>,
linux-media@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
Biju Das <biju.das.jz@bp.renesas.com>,
Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Subject: Re: [PATCH v2 2/5] media: i2c: ov5645: Use runtime PM
Date: Fri, 28 Oct 2022 22:05:01 +0100 [thread overview]
Message-ID: <CA+V-a8urGG-m-gn_sOhTJHhHws3X8zdgjq+YY8W7qy42VAdXgQ@mail.gmail.com> (raw)
In-Reply-To: <Y1rQBmXj71C1RrwB@paasikivi.fi.intel.com>
Hi Sakari,
On Thu, Oct 27, 2022 at 7:45 PM Sakari Ailus
<sakari.ailus@linux.intel.com> wrote:
>
> Hi Prabhakar,
>
> On Thu, Oct 27, 2022 at 05:32:07PM +0100, Lad, Prabhakar wrote:
> > Hi Sakari,
> >
> > On Thu, Oct 27, 2022 at 1:47 PM Sakari Ailus
> > <sakari.ailus@linux.intel.com> wrote:
> > >
> > > Hi Prabhakar,
> > >
> > > On Thu, Oct 27, 2022 at 01:01:52PM +0100, Lad, Prabhakar wrote:
> > > > Hi Sakari,
> > > >
> > > > On Thu, Oct 27, 2022 at 12:20 PM Sakari Ailus
> > > > <sakari.ailus@linux.intel.com> wrote:
> > > > >
> > > > > Hi Prabhakar,
> > > > >
> > > > > One more comment.
> > > > >
> > > > > On Fri, Oct 14, 2022 at 07:34:56PM +0100, Prabhakar wrote:
> > > > > > @@ -1209,12 +1190,16 @@ static int ov5645_probe(struct i2c_client *client)
> > > > > >
> > > > > > dev_info(dev, "OV5645 detected at address 0x%02x\n", client->addr);
> > > > > >
> > > > > > + pm_runtime_set_active(dev);
> > > > > > + pm_runtime_get_noresume(dev);
> > > > > > + pm_runtime_enable(dev);
> > > > >
> > > > > You won't gain anything by eanbling runtime PM here. Just move it to the
> > > > > end of the function before the rest of the calls. Error handling becomes
> > > > > more simple.
> > > > >
> > > > If I move the above calls below I get the below warning:
> > > >
> > > > [ 2.633386] ov5645 0-003c: Runtime PM usage count underflow!
> > > >
> > > > This is because of the last patch which moves ov5645_entity_init_cfg()
> > > > before registering the subdev. ov5645_entity_init_cfg() calls s_ctrl
> > > > due to which we are seeing the above message. Please let me know how
> > > > to proceed on this.
> > >
> > > Ah. Yes, this is a problem with the usage pattern of
> > > pm_runtime_get_if_in_use(). But please don't change that.
> > >
> > > You can still move enabling runtime PM later in the function.
> > >
> > Agreed, the final version looks like below:
> >
> > pm_runtime_set_active(dev);
> > pm_runtime_get_noresume(dev);
> >
>
> You'll have to enable runtime PM here, before pm_runtime_get_if_in_use()
> gets called.
>
> I'll see if it could be made to work in a sensible way when runtime PM
> isn't enabled yet.
>
Agreed, I'll send out v3 after fixing the comments.
Cheers,
Prabhakar
next prev parent reply other threads:[~2022-10-28 21:05 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-14 18:34 [PATCH v2 0/5] media: i2c: ov5645 driver enhancements Prabhakar
2022-10-14 18:34 ` [PATCH v2 1/5] media: dt-bindings: ov5645: Convert OV5645 binding to a schema Prabhakar
2022-10-14 21:00 ` Rob Herring
2022-10-14 21:05 ` Rob Herring
2022-10-14 21:27 ` Lad, Prabhakar
2022-10-14 21:40 ` Rob Herring
2022-10-15 5:54 ` Laurent Pinchart
2022-10-15 13:17 ` Krzysztof Kozlowski
2022-10-17 7:43 ` Lad, Prabhakar
2022-10-26 16:56 ` Rob Herring
2022-10-14 18:34 ` [PATCH v2 2/5] media: i2c: ov5645: Use runtime PM Prabhakar
2022-10-14 19:18 ` Sakari Ailus
2022-10-14 21:30 ` Lad, Prabhakar
2022-10-15 6:05 ` Laurent Pinchart
2022-10-15 6:25 ` Laurent Pinchart
2022-10-26 12:07 ` Lad, Prabhakar
2022-10-27 11:20 ` Sakari Ailus
2022-10-27 12:01 ` Lad, Prabhakar
2022-10-27 12:47 ` Sakari Ailus
2022-10-27 16:32 ` Lad, Prabhakar
2022-10-27 18:37 ` Sakari Ailus
2022-10-28 21:05 ` Lad, Prabhakar [this message]
2022-10-31 14:25 ` Sakari Ailus
2022-10-31 16:10 ` Lad, Prabhakar
2022-10-14 18:34 ` [PATCH v2 3/5] media: i2c: ov5645: Drop empty comment Prabhakar
2022-10-15 6:05 ` Laurent Pinchart
2022-10-14 18:34 ` [PATCH v2 4/5] media: i2c: ov5645: Return zero for s_stream(0) Prabhakar
2022-10-15 6:25 ` Laurent Pinchart
2022-10-15 21:35 ` Sakari Ailus
2022-10-15 23:23 ` Laurent Pinchart
2022-10-16 20:19 ` Sakari Ailus
2022-10-16 21:03 ` Laurent Pinchart
2022-10-17 7:12 ` Sakari Ailus
2022-10-17 7:40 ` Lad, Prabhakar
2022-10-14 18:34 ` [PATCH v2 5/5] media: i2c: ov5645: Call ov5645_entity_init_cfg() before registering the subdev Prabhakar
2022-10-15 6:26 ` Laurent Pinchart
2022-10-26 11:59 ` Lad, Prabhakar
2022-10-14 18:40 ` [PATCH v2 0/5] media: i2c: ov5645 driver enhancements Lad, Prabhakar
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